The invention relates to input/output method and apparatus for inputting and outputting a digital signal from a digital interface and, more particularly, to input/output method and apparatus for inputting and outputting a digital video signal or an audio signal.
According to a conventional digital signal recording and reproducing apparatus for recording a digital broadcast signal inputted from a digital interface, reproducing the recorded digital broadcast signal, and outputting it from the digital interface, upon recording, copy control information added to the digital broadcast signal is detected and a copy control regarding the recording of the digital broadcast signal is performed. Upon reproduction, the copy control information added to the digital broadcast signal reproduced from a recording medium is detected, and, for example, an encrypting process is executed in order to protect the signal which is outputted to the digital interface.
However, if the copy control information added to the digital broadcast signal indicates that the copy is possible (copy freely), upon recording, the signal is recorded onto the recording medium as a signal indicative of “copy freely” without being protected, and upon reproduction, the signal is outputted to the digital interface as a signal indicative of “copy freely” without being protected (encrypted). Therefore, even in case of the digital broadcast signal indicative of “copy freely”, if the user wants to inhibit the illegal use of the signal which is recorded onto the recording medium or the signal which is outputted to the digital interface, the illegal use of such a digital broadcast signal indicative of “copy freely” cannot be prevented. The “illegal use” used here denotes that the signal recorded on the recording medium or the digital broadcast signal outputted to the digital interface is tapped and distributed in a lump to many and unspecified persons without permission by using the Internet or the like.